[1] Erasmus Univ, Sch Med, Dept Epidemiol & Biostat, Rotterdam, Netherlands
[2] Mayo Clin Jacksonville, Dept Neurogenet, Jacksonville, FL 32224 USA
[3] Univ Rome La Sapienza, Dipartimento Sci Neurol, I-00185 Rome, Italy
[4] Univ Naples Federico II, Dipartimento Sci Neurol, Naples, Italy
[5] INSERM U289, Paris, France
[6] INSERM U358, Paris, France
[7] Univ Munich, Klinikum Grosshadern, Dept Neurol, Munich, Germany
[8] Univ London, Neurol Inst, Dept Clin Neurol, London WC1N 3BG, England
[9] Erasmus Univ, Sch Med, Dept Clin Genet, Rotterdam, Netherlands